WHAT IS DISTRICT ENERGY AND HOW DOES IT WORK? GORDON MONK

WHAT IS DISTRICT ENERGY AND
HOW DOES IT WORK?
GORDON MONK
Technology Integration Manager
BC Hydro Power Smart
Twitter hashtag: #ps10
AGENDA
1.
2.
3.
4.
5.
The Concept - What is District Energy?
The Benefits – Why Implement DE?
DE’s Challenges and Barriers
Clean Energy Sources
Profiles of Notable DE Systems
THE DISTRICT ENERGY CONCEPT
THE DISTRICT ENERGY CONCEPT
• A network of pipes that distribute thermal
energy from supplier(s) to consumers
• Network length can range from hundreds of
metres to hundreds of kilometres
• Number of customers can range 10 to hundred
of thousands
• Working “fluid” can be heated water, chilled
water or steam
• Consumer uses include (i) space heating (ii)
DHW heating and (iii) sometimes space cooling
HIGH TEMPERATURE (60o-120oC)
DISTRIBUTION PIPES
Prefabricated steel; external HDPE casings
sandwiched layer of insulating polyurethane
foam. Approximate Material Cost = $35 / ft
AMBIENT TEMPERATURE (5o40oC) DISTRIBUTION PIPES
•
•
•
•
Uninsulated
HDPE
Fewer leaks
No expansion
joints
Cheaper and
faster to install
Approximate
Material
Cost
= $4/ ft.
AMBIENT TEMPERATURE SYSTEM
CHARACTERISTICS/ REQUIREMENTS
• Compatible with waste heat recovery from low
temperature sources (Whistler Athletes’ Village,
Capital Regional District, Westhills)
• Compatible with large systems supplying dense
developments
• Require heat pumps or terminal units with large
surface areas (radiant floors or ceilings)
ENERGY TRANSFER STATIONS
Each connected building
requires:
One ETS (space heat)
Two ETS (space heat +
DHW)
Three ETS (space heat +
DHW + space cool)
Each ETS includes (i) HX,
(ii) flow control valve and (iii)
energy meter (flow + temp.
differential: supply/return).
HOW DOES DE SAVE ENERGY?
Facilitates steady, efficient base load
HOW DOES DE SAVE ENERGY?
• Large, centralized thermal generators (boilers
or combined heat + power units) tend to be
more efficient than smaller, distributed units.
• Commercial, residential and industrial
buildings have differing energy demand at
differing times. Aggregation flattens the load.
Typical diversity factor = 0.8
• A DE system can recover waste heat from
some customer and deliver it to other
customers.
LIMITED COOLING OPPORTUNITIES
• In BC, cooling demands are relatively low.
Economics are therefore challenging.
• Feasible cooling from lakes, rivers or the ocean
can be connected to major customers such as
schools, hospitals, a dense precinct of
commercial buildings, shopping centres and
convention centres.
• District cooling, like district heating, inherently
provides community energy planning
opportunities.
DE SYSTEM COSTS
Vary greatly according to location, density of
urban form, system size, thermal energy
sources, number of customers, etc.
System:
Capital Costs
($,000)
Operating Costs
($/MW.h)
Dockside Green
7,900
35
SEFC
43,200
58
BENEFITS FOR COMMUNITIES
1. Hot Swap Capability: heat-carrying network
fluid provides a common denominator for
multiple fuels - price spike and availability risks
are minimized.
2. Future Proofing: 100-year network lifespan
facilitates adoption of new technologies.
3. Waste heat recovery: economic capture from
industrial, municipal and commercial sources.
4. Biomimicry: Integrated, cascading energy
flows optimize community energy supply mix.
BENEFITS FOR COMMUNITIES
5. GHG (NOx, SOx, CO2, PM) reductions: clean
energy sources, local energy sources,
economy of scale w.r.t. mitigation
6. Energy security is enhanced
7. Local job creation (construction, operation
maintenance)
8. CAPEX containment: energy $ are re-invested
in the local economy and community-owned
systems provide public revenues
BENEFITS FOR CUSTOMERS
1. Reduced fuel price volatility
2. Increased revenue generating space
3. Reduced operating, maintenance and labour
costs
4. Reduced insurance rates
5. Increased reliability of service (99.98%)
6. Reduced noise & vibration
BENEFITS FOR BC HYDRO
1. Electricity savings from displaced residential
space heating (resistive baseboards) and
DHW loads where applicable
2. Combined heat and power (CHP) generators
that use renewable fuels provide clean sources
of electricity
3. Reduced transmission and distribution
investments
CHALLENGES AND BARRIERS
• High capital expenditure requirements
• North American costs are relatively high due to
equipment import requirements and lack of
construction expertise
• Out low thermal and electrical energy prices
• Public finances are currently constrained due to
weak economic conditions
• ROI is usually insufficient to attract private
equity partners
• Ability to connect future loads is uncertain
CHALLENGES AND BARRIERS
•
•
•
•
Potential customers are often risk adverse
Lack of technical expertise and technical skills
Uncertainty of future clean energy supplies
Lack of public awareness of DE features/
benefits
• Complexity of integrated community energy
planning process
• Resistance to increased density in smaller
communities
CLUSTERED vs. DISTRIBUTED
CENTRALIZED THERMAL GENERATORS
Lonsdale Energy Corporation’s Mini-Plants
WASTE HEAT AVAILABILITY
BC Hydro generates 194 PJ in a typical year.
In 2003, BC’s economy:
Consumed 566 PJ of useful energy
Lost 38 PJ of electrical energy (T&D losses)
Lost 532 PJ of thermal energy (waste heat)
BC loses as much heat as it consumes in the
form of electricity and heat.
NRCan estimates 22% or 116 PJ is technically
recoverable.
WASTE HEAT RECOVERY
Industrial Waste Heat
Technology: Organic
Rankine Cycle.
Where: Cement kilns,
sawmill lumber dryers,
food processing plants.
Scale: Medium to large
source of heat.
WASTE HEAT RECOVERY
Organic Rankine Cycle (ORC)
Regenerator
Organic ~ hydrocarbon or refrigerant with a
boiling point below that of water
SEWER HEAT RECOVERY
Technology: Heat pumps
extract heat from municipal
sewer system.
Where: Large sewer trunks,
pump stations or outflow
pipes.
Scale: Small to large. Can
range from home-size heatpumps extracting heat from
local sewer main, to large
plants at pump stations.
BIOMASS - TYPES
• Agricultural waste – primarily straw
• Urban wood waste – sawn lumber & demolition
debris, shipping pallets, pruned branches,
stumps & whole trees from streets & parks
• Industrial wood waste – sawdust, chips
• Mountain pine beetle kill – wood pellets
• Short rotation intensive culture forestry – hybrid
poplars & aspens, Siberian larch,silver birch
• Short rotation woody crops – intensive culture of
fast growing species (alder, poplar, willow)
• Herbaceous crops – switchgrass, prairie tall
grass, hemp, sorghum, reed canary grass,
alfalfa, bromegrass
COGENERATION OR COMBINED
HEAT AND POWER (CHP)
• Simultaneous generation of useful heat and
power from a single fuel or energy source
• Optimized design meets the thermal demand of
the building cluster, campus, precinct,
neighborhood or community
• Key advantage over separate generation of heat
and electricity is higher efficiency – up to 93%
SMALL-SCALE BIOMASS
GASIFICATION CHP
Technology: ‘cooking’ of solid
wood to create synthetic
biogas that is used to
generate electricity
Where: Wherever you can
receive and store large
quantities of wood, often near
a heat customer
Scale: Medium. Not more
than 5,000 homes worth of
electricity
LARGE-SCALE BIOMASS CHP
Technology: Generates steam that drives a turbine.
Where: Wherever you can receive and store large
quantities of wood, often near a heat customer.
Scale: Big. Usually supply more than 30,000 homes
with electricity.
THERMAL STORAGE
Short term technology: Insulated water tanks
above ground
Long term technology: Underground thermal
energy storage (UTES)
Natural UTES: Aquifer thermal energy storage
(ATES)
Artificial UTES: Gravel and water pits. Borehole
thermal energy storage (BTES). Buried steel or
concrete tanks.
CASCADE ENERGY FLOWS
Commercial
District Energy Station
Retail
Residential
(MURB or
Detached)
METROPOLITAN COPENHAGEN
HEATING TRANSMISSION COMPANY
EVER-GREEN ENERGY – ST. PAUL
WHISTLER ATHLETES’ VILLAGE
Ambient temperature system.
Heat is recovered from treated
waste water effluent using heat
exchangers.
Reversible distributed HPs
upgrade heat to 65oC for
space/ DHW inside the
buildings.
HPs will also extract heat in
summer for discharge.
Predicted overall energy
consumption reduced > 50%.
GHGs reduced by 96%.
SOUTHEAST FALSE CREEK
Central heat pumps recover
thermal energy from
sewage influent to waste
water treatment plant.
The recovered heat is
distributed though the DE
loops at temperatures
ranging from 70oC - 90oC.
ETSs transfer heat for
space and DHW heating.
BC HYDRO DE PROGRAM
Support for eligible projects:
(i) Pre-feasibility study.
(ii) Feasibility study.
(ii) Capital incentives.
When we work together, knowledge, experience and
innovation can “Lead the Way to a Sustainable
Future.”
THANK YOU!
GORDON MONK
604.453 6547
[email protected]
Twitter hashtag: #ps10
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